The decision to give apprentice jockey Jerlyn Seow Poh Hui a leg-up on $10 favourite Mortal Engine in the $50,000 Class 4 Division 1 race over 1100m proved the right one for the Michael Clements camp on Saturday.

Assistant-trainer Michael White revealed much to-ing and fro-ing had gone on before they booked Seow on the Unencumbered four-year-old at his three-in-a-row bid.

The three-kilo allowance was the main draw given the 59kgs top impost Mortal Engine  had been slapped with, but the Singaporean lass's relative inexperience could offset that advantage.

After weighing up the pros and cons, Clements and White were in the end swayed by a previous ride from Seow on one of their horses, The Shadow. They took a punt which eventually came off, albeit not without a few nerve-wracking seconds inside the last strides.

Happy Moment (Troy See) came steaming home at the rate of knots, but missed out by a short head. Bionics (Iskandar Rosman) finished third another 2 ¼ lengths away. The winning time was 1min 5.45secs for the 1100m on the Polytrack.

"Jerlyn rode the horse very well. She didn't panic when she sat outside the other horse (Opunake) who wouldn't let her cross," said White.

"We were a bit hesitant to put her on but she rated The Shadow  very well at his last start, and we thought she deserved a chance on that. She has really improved as a rider.

"This horse is no star, but he's a natural runner and he makes his own luck in front. He's now won three in a row on Poly, he's had a bit of luck.

"He did have a good win on turf at his debut. He reminds me of Ablest Ascend, who had a similar career here."

Seow currently leads the Singapore apprentice jockey's leaderboard on four wins, two clear of former two-time champion Simon Kok Wei Hoong.

Happy Moment  might have made it interesting late, but the second-year rider was rather confident she had winner No 4 safely tucked away.

"The other horse only came up after the line, so I knew I had won," said Seow.

"I was told this horse hangs out, but he was keeping a straight line throughout today. That's why I was happy to hold my position outside the leader.

"In the straight, he responded very well and was very brave to the line."

In five starts, Mortal Engine has now racked up four wins for stakes money that have hit past the $120,000 mark for the Tivic Stable.